Ecommerce would include:
7. Woocommerce
8. Shipping plugins such as USPS/FexEx/) whatever is necessary
9. A payment gateway if not using PayPal.

I’ve also used “Members” for user role restriction.

Sliders, custom galleries, cool effects and such don’t get plugins, they get coded into the theme so that I can optimize them better, and have fewer plugins to maintain. I try like hell to keep any custom functionality, such as faq pages, company directories, etc… custom coded and in the mu-plugin as well.